Southern California -- this just in

Small earthquakes still rumbling Southern California

Small earthquakes continued to rumble Yorba Linda early Thursday after a series of more than 30 quakes — highlighted by two magnitude 4.5 temblors — rocked the area in recent hours.

Seismologists said an "earthquake sequence" centered near the Whittier fault began with the first 4.5 quake, which struck about a mile north of Yorba Linda about 11:30 p.m. Tuesday. A 2.0 aftershock that immediately followed was one of many to come, rattling the region but causing no major damage.

The second magnitude 4.5 hit about 9:30 a.m. Wednesday, again causing no significant damage, although Ontario officials said a garage explosion occurred after the quake caused some items to fall, opening a natural gas valve in the process.

The aftershocks continued, including a magnitude 3.4 about 30 minutes later, according to data from the U.S. Geological Survey. The most recent quake to center near Yorba Linda — measuring a magnitude of 1.5 — hit about 12:45 a.m. Thursday.

At a news conference Wednesday morning, Kate Hutton of the USGS said residents probably only felt three of the quakes. The two 4.5 temblors were felt across a wide swath of Southern California, with people reporting shaking as far away as Thousand Oaks, the Santa Clarita Valley, the Westside and northern San Diego County, according to the USGS' Did You Feel It? website.

"It shook us pretty good," said Chris Nordyke, director of marketing at the Richard Nixon Library and Birthplace in Yorba Linda. "We've felt earthquakes before, so it came as no surprise."